Process of roasting ores and recovering zinc therefrom.



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CHARLES J'. REED, O-F PHILADELPHIA, PENNSYLVANIA.

PROCESS OF ROASTING ORES AND RECOVERING ZINC THEREFROM.

No Drawing.

To all whom it may concern:

Be it known .that I, CHARLES J. REED, a citizen of the United States,residing at Philadelphia, in the county of Philadelphia and State ofPennsylvania, have-invented certain new and useful Improvements inProcesses of Roasting Ores and Recovering Zinc Therefrom, of which thefollowing is a specification.

My process relates to the conversion of sulfid ores into sulfates, andthe recovery of the metals from the sulfates by solution in water andacid. It is particularly adapted to the treatment of mixed sulfids 'ofzinc, iron, manganese, lead, copper, cadmium'and other metals,containing or not containing gold or silver or both. In the ordinaryprocess of roasting such ores, it is customary not to grind the ore to avery small size, and to avoid as much as possible the production of finedust. The granular ore is gradually raised to a high temperature incontact with air, and is stirred continuously or at frequent intervals,the final temperature being a bright red, nearly a white heat. In thisprocess only a small percentage of sulfid is converted into sulfate,most of-it being converted into oxid, with the burning out of sulfur andthe production of sulfur dioxid, which escapes.

In my process the ore is first ground to a very fine powder or dust, thefiner the better. I find it advantageous to reduce it to a size thatvwill'pass through a screen having 150 or 200 holes to the linear inch.The ore is' then thoroughly mixed with a suitable quantity 0.." asuitable metallic oxid,

such as zinc oxid or iron oXid, also reduced to a state of minutesubdivision. The mixture of ore and oXid is then heated in contact withair for several hours, at a dull red heat, until there is no furtherchemical The soluble sulfate is then dissolved oiit with water. Therewill also-generally be simultaneously produced a quantity of basicsulfate and sulfite, which may be, dissolved by dilute ormoderately-conceii'trated acid but'not by water alone. The

zinc, copper, cadmium and some of the other.

Specification of Letters Patent.

Application filed June 3, 1912.

Patented Aug. 5,1913.

Serial No. 701,300.

tained in solution, from which the 'various metals may be separately orcollectively recovered, either by electrolytic or other methods. ofprecipitation.

I do not limit myself to the use of the particular oxids hereinmentioned, since others may serve the same purpose. A convenient andefiicient oXid reagent is the previouslyroasted and leachedore-residue,consisting chiefly of iron oxid.

l/Vhile I do not limit myself to any par .ticular proportions in themixture of ore and oxids, one part by Weight of oxid totwo parts of oreis found to be efiicient, al-:

though almost any proportion'may be used to producea result of the samegeneral character.

I- do not limit myself to any particular method of recovering the metalfrom the solution, but prefer; in the case of zinc, to deposit the metalelectrolytically, using an anode of spongy lead, which electrochemicallybinds the liberated sulfuric acid. In this case, I first purify thesolution'by treating itwith oxidizing agents, zincoxid and metalliczinc, as described in another application filed simultaneously herewith.

I claim 1. The process oftreating metallic sulfids,

which consists in reducing them to a fine powder, mixing the powder witha material containing a metallic oxid, and sub ect1ng the mixture toheat in the presence of an oxid, in air, dissolving out theresultingcompounds, and recovering zinc from the solution.

In testimony whereof I amt; my signature 1n presence of two W1t11esses.

CHARLES J. REEI 4. The p'roeess of reeofiering zinc from zine sulfid,which consists in heating the powdered material, mixed with a previouslynXiihZQd portion of. similar material, in

I \Vitnessesz. FRANK A. LEACH, l .T. M. JACKSON.

an. nxidizing ntmemphere, dissolving out the resulhng compounds, andrecovering zmc Fa-mu the SOhlUUD.

Copies of -this patent may be obtained fer five cents each, byaddressing the Commissioner of 'Eafients.

Washingten, D. C.

